Every new Doosan machining center, horizontal or vertical, comes with a BIG-PLUS® spindle as a standard feature. While other machine tool builders may offer dual-contact spindles as an option, we want our customers to have every performance advantage on every machine.
Why did we choose a dual contact spindle? A conventional steep taper tool holder (like a CAT 40) is only supported by one connection: the tool holder taper to spindle taper. The BIG-PLUS Spindle System provides dual contact between both the spindle face and the flange face of BIG-PLUS tooling available from BIG KAISER. This provides superior rigidity, and is key to reduced runout at high speeds, better surface finishes and longer cutting tool life.
Conventional CAT40 and CAT50 tool holders can be used in BIG-PLUS spindles and are fine for less aggressive applications, but dual-contact makes BIG-PLUS tool holders ideal for milling applications involving heavy radial loads or long projections such as milling deep cavities.
Providing a best-in-class spindle as standard on every machining center may seem like overkill, but if it means additional value for our customers, we’re good with that. To see for yourself why we selected BIG-PLUS as our standard spindle system, check out this video that shows a side-by-side comparison between the BIG-PLUS and a conventional spindle.